Ventilação mandatória contínua modo volume controlado: análise de desempenho essencial de ventiladores pulmonares quando submetidos a quatro cenários da norma ABNT NBR ISO 80601-2-12.

Abstract

Pulmonary ventilators have received great attention in recent years due to the impact of health scenario the world faced. These devices and their ventilatory modes are responsible for providing safer and more effective ventilation in the most diverse respiratory conditions that can affect a patient. Among the ventilation modes available in critical care ventilators there is the Continuous Mandatory Ventilation mode with volume control (CMV-VC), used in patients whose respiratory effort is null, such as in situations of neuromuscular blockade. In this mode, the ventilator aims to ensure the delivery of a volume to the patient's lung, changing its flow and pressure parameters and monitoring this delivery. Ventilatory modes have been evaluated by researchers over the years and their operational oscillations have been documented while the equipment is bench-tested. However, some works found in the literature adopt scenarios for assessing ventilatory performance that are different from each other, regarding the metrics, methodology and equipment configurations adopted. In addition, many of these studies analyze models of high-cost ventilators, which, generally, is not the reality found in a large part of the Brazilian territory. Thus, this dissertation has the main purpose of comparing the ventilatory parameters and their waveform patterns of five different lung ventilators found in the Brazilian scenario when they are operating in CMV-VC mode. It is also intended to detail the entire methodology in which the measurements were carried out and to evaluate the essential performance of this equipment considering the technical standard ABNT NBR ISO 80601-2-12: 2014 as a premise. A data acquisition system with a sampling frequency of 100 Hz obtained flow and pressure data from each device. The setup of the experiment present in the ABNT NBR ISO 80601-2-12: 2014 standard was used so that the tests were carried out in four scenarios for evaluating the CMV-VC mode, in which lung compliance and resistance varied in different combinations. For all scenarios, the volume to be delivered should be 500 mL. Positive end-expiratory pressure (PEEP) and inspiratory time (Tins) parameters were also evaluated. Despite being submitted to the same four scenarios, ventilators showed differences in PEEP and volume parameters, while Tins behaved similarly in all situations. Positive endexpiratory pressure (PEEP) and inspiratory time (Tins) parameters were also satisfactory. Despite being tolerant of the same four scenarios, ventilators differed in PEEP and volume parameters, especially in scenarios 3 and 4 where compliance and lung resistance were higher. Tidal volumes ranged from 381.49 to 591.15 mL, PEEP from 3.58 to 3.75 cmH2O in scenarios 1 and 3 and from 8.37 to 9.61 cmH2O in scenarios 2 and 4, while Tins ranged from 0.86 to 1.05 s in the measurement system proposed by the standard. Additionally, a mechanical ventilation evaluation system, commercially available in the national market, was used and the results were compared.